In the field of microwave signal propagation, there is a need to amplify the signal in order to increase the power of the signal. In order to do so, microwave monolithic integrated circuit (MMIC) power amplifiers are typically used. These amplifiers typically have a specific power gain that allows the input signal power to be amplified. There are certain applications, however, that require higher power handling capability than the typical MMIC power amplifier can handle. In this case, it is desirable to use a signal power divider/combiner device. A power divider takes in the signal to be amplified and then divides it into a number of output signals, such that the power in the input signal is equally divided among these output signals. Each of these output signals at reduced power can be equally amplified by an amplifier that can handle a relatively lower signal power, with each signal being routed to a separate amplifier. Finally, the outputs of these power amplifiers are collectively input to the RF signal combiner, wherein these amplified signals are combined to form the required output signal.
As an example, consider a signal having a power of 10 Watts, which needs to be amplified to 1000 Watts—a required amplifier power gain of 100. In this example, the current application is limited to using power amplifiers that can handle 300 Watts or less signal power. Without the use of a power divider/combiner device, it is not possible to get the output signal of the required power. In this case it is useful to divide the input signal using a power divider into, for example, four parts. Thus, the power divider outputs four signals, each 2.5 Watts in power. Each of these signals can be amplified by a gain of 100, to an output of 250 Watts, lower than the 300 Watt rating of the power amplifier. Finally, these four signals of 250 Watts each can be routed to the inputs of a power combiner to give the required output signal of 1000 Watts.
While the above example demonstrates the advantage of using waveguide power dividers and combiners, it must be noted that existing waveguide power combiners are ultimately power limited. Further, existing devices are also bandwidth limited—there is a limit to the range of frequencies that can be handled by the device. The present invention addresses the limitations of existing waveguide power dividers and combiners by designing a waveguide structure that allows for a greater power handling capability as well as an increase in bandwidth.